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1 /* | |
2 * Copyright (c) 2017 The WebRTC project authors. All Rights Reserved. | |
3 * | |
4 * Use of this source code is governed by a BSD-style license | |
5 * that can be found in the LICENSE file in the root of the source | |
6 * tree. An additional intellectual property rights grant can be found | |
7 * in the file PATENTS. All contributing project authors may | |
8 * be found in the AUTHORS file in the root of the source tree. | |
9 */ | |
10 | |
11 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_TEST_ANALOG_VOLUME_MAPPER_H_ | |
12 #define WEBRTC_MODULES_AUDIO_PROCESSING_TEST_ANALOG_VOLUME_MAPPER_H_ | |
13 | |
14 #include "webrtc/base/checks.h" | |
15 | |
16 namespace webrtc { | |
17 | |
18 // Class for simulating an analog gain controller controlled by | |
19 // webrtc::GainControl. The class wraps a mapping from the current | |
20 // level to a floating point scaling factor abstracting | |
21 // non-linearities in the gain curve of real analog microphones. The | |
22 // intended mode of operation is to use get_scaling_factor() to apply | |
23 // a gain factor to a signal. | |
24 class AnalogLevelMapper { | |
25 public: | |
26 enum class LevelToScalingMappingKind { | |
27 kIdentity, // Any level produces a | |
AleBzk
2017/04/24 14:54:30
The comment looks incomplete.
aleloi
2017/04/25 08:23:58
Thanks, done.
| |
28 kLinear // A level within [0, 255] is linearly scaled. 0 produces | |
29 // 0.f, and 255 is 1.0f. | |
30 }; | |
31 | |
32 explicit AnalogLevelMapper(LevelToScalingMappingKind mapping_kind) | |
33 : mapping_kind_(mapping_kind) {} | |
34 | |
35 bool AnalogLevelIsValid(int level) { | |
AleBzk
2017/04/24 14:54:30
From this method, I understand that different mapp
aleloi
2017/04/25 08:23:58
I couldn't find a range outside 0, 255 except in t
| |
36 switch (mapping_kind_) { | |
37 case LevelToScalingMappingKind::kIdentity: { | |
38 return level_ <= 65535 && 0 <= level_; | |
AleBzk
2017/04/24 14:54:30
You probably want to check level and not level_.
aleloi
2017/04/25 08:23:58
Oh, good catch! Done.
| |
39 } | |
40 case LevelToScalingMappingKind::kLinear: { | |
41 return level_ <= 255 && 0 <= level_; | |
AleBzk
2017/04/24 14:54:30
Same here
aleloi
2017/04/25 08:23:58
Done.
| |
42 RTC_DCHECK_LE(0, level_); | |
43 } | |
44 } | |
45 } | |
46 | |
47 // As the analog level limits in webrtc::GainControl, |level| must | |
48 // be within [0, 65535]. | |
49 void set_analog_level(int level) { | |
50 RTC_DCHECK(AnalogLevelIsValid(level)); | |
51 level_ = level; | |
52 } | |
53 | |
54 int analog_level() const { return level_; } | |
55 | |
56 float GetScalingFactor() const { | |
57 switch (mapping_kind_) { | |
58 case LevelToScalingMappingKind::kIdentity: { | |
59 return 1.0f; | |
60 } | |
61 case LevelToScalingMappingKind::kLinear: { | |
62 return static_cast<float>(level_) / 255.0f; | |
63 } | |
64 } | |
65 } | |
66 | |
67 private: | |
68 int level_ = 0; | |
69 const LevelToScalingMappingKind mapping_kind_; | |
70 }; | |
71 } // namespace webrtc | |
72 | |
73 #endif // WEBRTC_MODULES_AUDIO_PROCESSING_TEST_ANALOG_VOLUME_MAPPER_H_ | |
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